Stencil mask, production method thereof, exposure apparatus, exposure method and electronic device production method

Abstract

A stencil mask capable of effectively reducing a dimension of apertures to be a mask pattern while preventing damages on a pattern formation layer and variations of positional accuracy of the apertures, and the production method, and an exposure apparatus and an exposure method capable of performing exposure of a fine pattern on a layer to be exposed by using the stencil mask, and a production method of an electronic device are provided: wherein a dimension control layer is formed on all surface of the pattern formation layer including apertures for a charged particle beam to transmit by an isotropic film forming method, so that a dimension of the apertures to be a mask pattern substantially is reduced exactly by a film thickness amount of the dimension control layer from a dimension of apertures formed by using a mask drawing machine; and it is preferable that the dimension control layer has conductivity and is made of a material having an approximately same linear expansion coefficient with that of the pattern formation layer.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a stencil mask for lithography using a charged particle beam, the production method, an exposure apparatus and an exposure method using the stencil mask, and an electronic device production method. [0003] 2. Description of the Related Art [0004] In recent years, as an integrated circuit becomes higher in density, limitations have been pointed out on photolithography which has been a mainstream of fine pattern formation techniques. To overcome the limitations, lithography by an electron beam (an electron beam exposure apparatus) has been rapidly advanced. [0005] Particularly in an electron beam projection exposure apparatus and an electron beam proximity exposure apparatus, a mask having a thin membrane having a thickness of 300 nm to 2 μm formed by SiC, Si or diamond is used. In the mask production method, by applying a resist to the membrane layer, transferring a pattern by an elect...

AI Technical Summary

Benefits of technology

The present invention provides a stencil mask that can effectively reduce the size of apertures while preventing damage to the pattern formation layer and positional accuracy variations. The stencil mask comprises a pattern formation layer with a pattern of apertures for a charged particle beam to transmit and a dimension control layer covering the inner walls of the apertures to reduce their size. The stencil mask can be used in an exposure apparatus to form a fine pattern on a layer to be exposed. The production method of an electronic device using this stencil mask allows for a more compact and integrated electronic device.

Problems solved by technology

In recent years, as an integrated circuit becomes higher in density, limitations have been pointed out on photolithography which has been a mainstream of fine pattern formation techniques.

Particularly, a mask used in the electronic beam proximity exposure apparatus is an unmagnified mask.

It is necessary to use the latest drawing machine for producing such a pattern, but those satisfying the specification are few, and if any, they are very expensive.

Furthermore, it is also required to produce a pattern exceeding resolution limitations of the mask drawing machine due to miniaturization, which is naturally impossible to attain with the mask drawing machine.

Also, the latter faces a high technical obstacle and results in a very expensive apparatus even if it is overcome.

However, there are disadvantages that cross-linking of the fine pattern formation material arises also in an unnecessary portion of the bottom part of the resist pattern, perpendicularity of a sectional shape of the fine pattern formation material becomes defective, or a dimension of an upper resist pattern varies due to mixing bake for inducing cross-linking.

Also, the processes exhibit high heat dependency of 10 to 19 nm / C°, and it is hard to maintain a uniform temperature on the wafer when the substrate becomes larger and the pattern becomes finer, so that there is a disadvantage that controllability of a dimension of an obtained pattern declines.

However, this method has a disadvantage that control of fluidity of the resist by heat or a radiation ray is difficult and products with consistent quality cannot be obtained.

However, the water-soluble resin, such as polyvinyl alcohol, used in the method has a disadvantage that solubility and stability over time required at being removed by water are insufficient and residual is generated.

On the other hand, in the method of shrinking the resist explained above, a membrane is highly liable to be damaged, for example, by being imposed a compression stress on apertures and a contraction stress on resist portions when subjected to heat contraction, etc.

Also, there is a disadvantage that positional accuracy of apertures is deteriorated by internal stress variation of the membrane.

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